The present invention relates to improvements in apparatus for manipulating bobbins or reels of convoluted flexible web- or strip-shaped material. More particularly, the invention relates to improvements in apparatus for engaging and advancing the leaders of webs which are convoluted on the cores of reels and must be withdrawn in order to be transported along a predetermined path, especially toward and through a splicing device which can connect the leader with a second web. Such apparatus can be utilized with advantage in tobacco processing machines, for example, in cigarette making, filter tipping and filter rod making machines wherein webs of cigarette paper, imitation cork or other flexible wrapping material are draped around rod-shaped fillers or are convoluted around the abutting end portions of coaxial rod-shaped articles.
It is well known to store a fresh reel of convoluted cigarette paper or other suitable wrapping material on an indexible carrier which also supports a second reel adjacent to the fresh reel. The reels are mounted on suitable spindles, and the web of the expiring reel (namely of the reel whose web is being fed into the web-consuming machine) is spliced to the leader of the fresh web before the supply of web on the expiring reel is exhausted. In many instances, fresh reels are supplied with protective bands or strips which surround the outermost convolutions of convoluted webs of wrapping material. Such protective bands must be severed in order to afford access to the leaders of the respective webs so that the leaders can be transported to the splicing station where they are about to be connected to the running webs of the expiring reels. In many instances, the means for severing the protective band on a fresh reel is designed to simultaneously sever one or more outermost convolutions of the web of wrapping material so that the actual leader of the web on the fresh reel is the free end of the second, third or further outermost convolution of the fresh reel. This reduces the likelihood that a damaged or contaminated portion of the web, which is being withdrawn from a fresh reel, will enter the web processing or consuming machine.
A modern tobacco processing machine, such as a cigarette making machine, turns out extremely large numbers of rod-shaped articles per unit of time. For example, a modern cigarette maker can turn out up to and even in excess of 8000 plain cigarettes of unit length per minute. The output of many recent types of filter rod making and filter tipping machines is also very high. Consequently, the reels of convoluted wrapping material (be it cigarette paper, tipping paper or any other kind of flexible material which is used in a tobacco processing machine) must be replaced at frequent intervals. The period of time which is available for replacement of an expired reel with a fresh reel, so that the web which is convoluted on the fresh reel enters the consuming or processing machine without any interruption upon termination of withdrawal of the web from the preceding reel, is extremely short. It has been found that the most time-consuming operation in connection with the replacement of expiring reels of wrapping material with fresh reels is the preparation of a freshly inserted reel for splicing to the web which is being paid out by the preceding or expiring reel. Such preparation involves removal of the aforementioned protective band as well as advancement of the thus exposed leader of the web on the fresh reel into the range of the splicing mechanism. Presently known apparatus which are used to prepare the webs of fresh reels for attachment to the webs of expiring reels are simply incapable of ensuring proper treatment of the leaders of fresh webs within the allotted extremely short intervals of time which are available in a modern cigarette making, filter tipping or filter rod making machine. In other words, even if such conventional apparatus are operated at the maximum speed of which they are capable, this still does not suffice to ensure predictable and accurate placing of the leader of the web on a freshly installed reel into an optimum position with reference to the splicing mechanism.